ASP.NET Pages Displayed Blank Due To Cache - asp.net

Question

We recently updated a Joomla site running on IIS, which has a menu item that opens an ASP.NET Framework 4.8 page in an iframe. This page opens on every browser I've tested on multiple machines. The problem is that since yesterday when the new site was deployed, some users are reporting a blank page when accessing the new menu item. In most cases, asking the user to clear their cache will allow them to view the page. Most of the problems were with Chrome browsers, but this is probably due to it being the most popular browser.
So I think there is a caching problem on the web site with the ASP.NET page. I suspect that the few users who are having problems never close the web browser on their machine (most are business users). Is there a way force pages to expire and reload in an ASP.NET page?
Thanks.

Answer 1

You could loop through all the cache items and delete them one by one:
foreach (System.Collections.DictionaryEntry entry in HttpContext.Current.Cache)
{
HttpContext.Current.Cache.Remove(string(entry.Key));
}
Syntax Correction for ASP.NET 4.5 C#
foreach (System.Collections.DictionaryEntry entry in HttpContext.Current.Cache){
HttpContext.Current.Cache.Remove((string)entry.Key);
}

Answer 2

To expire web content, you can use some iis feature like Client Cache or output cache.
Client Cache:
This element specifies cache-related HTTP headers that IIS 7 and later sends to Web clients, which control how Web clients and proxy servers will cache the content that IIS 7 and later returns.
to set you can follow the below steps:
Open the iis manager.
Select the site or application.
Select the HTTP Response Headers feature.
In the HTTP Response Headers pane, click Set Common Headers... from the Actions pane.
In the Set Common HTTP Response Headers dialog box, check the box to expire Web content, select the option to expire after a specific interval or at a specific time, and then click OK. You can set time of expiration.
For more detail about output cache and client cache you can refer below article:
Client Cache
IIS Output Caching